Gauge for tapered pipe thread



Jan. 18, 1944. L HUSBAND 2,339,699

GAUGE FOR TAPERED PIPE THREAD Filed Nov. 10, 1942 3m entor 9 I 7 1/ 9! attornegs with a slot l8. Toward Patented Jan. 18, 1944 assasss canes ron 'raranan mra mean Linton A. Husband,

Elmhurst, 111., assignor to General Motors Corporation, Detroit, Mlcln, a

corporation of Delaware Application November 10, 1942, Serial No. 465,099

a claims. (Ci. 33-199) An improved gauge for testing tapered pipe thread is the subject matter of this invention.

The object sought to be. attained is the Provision of a gauge by the use of which tapped pipe threads ed and the measured.

Another object is to provide such a gauge which is simple, requires no adjustments and by the use of which even an inexperienced shopman may perform the required tests.

The accompanying drawin ment of the gauge.

In the drawing:

Figure 1 is a transverse sec instrument.

Figure 2 is a transverse section at right angles to the section of Figure 1.

Figure 3 is a sectionlike that of Figure 1. the larger scale showing how the instrument is used.

Figure 4 is a detail in perspective of one of the parts.

The gauge is made up of two parts. One part marked I may be called the thread gauge. It has a shank 8 terminating in an enlarged end II. The end ll is threaded as at portion will be an exact duplicate of a standard National Tapered Plug gauge. It is formed with a gauging notch marked I! and with milled fiats l1. Intermediate its length the shank is formed the opposite end the shank is reduced forming a shoulder or-mark 2!. At the end of the shank i a handgrip 23 secured by a pin 25. 3 v

Surroundln the thread gauge is a truncation gauge designated as a whole by numeral 21. It is a tubular member with a pin 20 traversing the depth of the threaded opening shows an embodiion through the slot it of the thread gauge whereby there is a limited relative axial movement of the two parts I and 21. The work end of trimcation gauge is tapered as at II. This tapered end is slotted forming furcations 33 forming with the fiatted head I i of the thread gauge a provision for rela-'- tive sliding but non-rotating movement between the two parts I andll. The outer surface of part 21 is preferably'knurled and the extreme end is notched to form a gaugin P rtion having faces 28 and ".j

The alignment is substantially perfect owin to the sliding fit of 'part 1 and 21. v No cocking of the truncation gauge can take place. Testing is made without resort to dials or vernier attachments making its use a very simple matter. All parts are readily constructed and if and when they become worn they can readily be chrome plated and reground to size.

The operation is very simple. The thread auge is threaded into the opening having the tapered thread. The position of the notch ll measures the depth of the threaded opening and maybe gauged. the truncation test- It. The threaded its diameter. The notch II is so formed that the surface of the threaded opening should lie between points on the gauge marked a and b. Thereafter the truncation gauge is reciprocated so that its sloping face c mined by the position of 2| on the thread gauge relative to the faces gauge. These are so formed that if notch li lies between faces 28 and II the truncation is accurate within the limits provided.

Iclaim:

l. A gauge to measure a tapered pipe thread comprising a stem having at one end a standard a sleeve slidable thread to form a thread gauge, along and about but non-rotatable relative to said stem and having adjacent said standard thread a conical end forming a truncation gauge,

I a formation on the thread gauge adjacent its thread" gauge thread to determine by its relation to the surface of the threaded opening of the pipe when threaded therein the diameter of the surface of the opening and the depth of the opening and cooperating formations on the thread gauge and truncation 'gauge and spaced axially from said stem threads to test the truncation of the threaded opening.

2. The invention defined by claim 1, said first mentioned formation on the thread gauge comprising a notchon the threaded end thereof.

3. The invention defined by claim 1, said cooperating formations eomprising a marker on the and spaced limiting faces on the truncation gauge.

4. In a pipe thread gauge device, a thread gauge having threads at one end, a truncation gauge having a conical end adjacent said first mentioned gauge threads, means to provide said auges with limited relative axial but non-rotative movement, a formation on said thread gauge adjacent its threaded end to measure the depth of the pipe thread opening by reference to surface of said opening and cooperating formations on said thread gauge and truncation gauge to determine the truncation of. said threaded opening, said last mentioned formations bein axially spaced from said first mentioned forma- 5. The invention defined by claim 4, said truncation gauge being a sleeve slidable on said thread gauge and having a tapered end to contact the crests of the pipe threads.

. 6. The invention defined by claim 4, said thread gauge comprising a stemTeiminating'with an enlarged, flatted and threadedend and said tapered end of the truncation gauge formed with furcations whereby said truncation gauge is slidably related to the flatted end of said thread gauge.

mimosa.

, lies on the crests of the teeth. The accuracy of truncation is deter-- 28 and 30 on the truncation. 

